Add Vita PSP-Emulator Keys

[Spenon-dev]

Keys to decrypt all firmware prx files of the Vita PSP emulator found in pcff.elf.
Verified and tested against all retail firmwares.
Should also decrypt all prx files from DEX/TOOL firmwares but not all have been tested.

Closes #40

[LiEnby]

i cant seem to decrypt the os0:kd/pcbc.skprx, which is loaded right after pcff.skprx, (if i had to guess id think its probably the IPL ..?) tried?: pspdecrypt -i psvita.ipl --version 661 -o psvita.ipl.dec
(where psvita.ipl is segment 1 from pcbc.elf)

actually, i cant decrypt IPL from any psp firmware with this?

[Spenon-dev]

i cant seem to decrypt the os0:kd/pcbc.skprx, which is loaded right after pcff.skprx, (if i had to guess id think its probably the IPL ..?) tried?: pspdecrypt -i psvita.ipl --version 661 -o psvita.ipl.dec (where psvita.ipl is segment 1 from pcbc.elf)

actually, i cant decrypt IPL from any psp firmware with this?

Sorry for the late reply,
Yes os0:kd/pcbc.skprx is the IPL. The encryption is unique to the Vita and pspdecrypt does not support it at the moment.
Theres a way to decrypt it however.

1. Strip the first 304 Bytes of the pcbc.skprx file.

2. Then use this tool to decrypt it.
   https://github.com/TheOfficialFloW/VitaMips/tree/master/pcbctool

The XOR key in pcbctool must match the firmware version. You can find the keys here
https://playstationdev.wiki/psvitadevwiki/index.php/Keys#ePSP_IPL_Xor_Keys

This functionality could of course be merged into pspdecrypt but I don't know
if it is worth the extra complexity for this niche case.